Detection system for sheets of paper or the like



R. BUCKHOLZ Feb. 27, 1968 DETECTION SYSTEM FOR SHEETS OF PAPER OR THE LIKE Filed July 12, 1965 2 Sheets-Sheet 1 FIG.

RONALD R. BUCKHOLZ Feb. 27, 1968 DETECTION SYSTEMFOR SHEETS OF PAPER OR THE LIKE Filed July 12, 1965 2 Sheets-Sheet 2 I IOV POWER SUPPLY FIG. 3

LOW VOLTAGE SOURCE 8V INVENTOR RONALD BUCKHOLZ ATTORN YS designated 26,

United States Patent 3,371,331 DETECTION SYSTEM FDR SHEETS OF PAPER OR THE LIKE Ronald Buckhoiz, Bay Shore, .N.Y., assignor to Mailmcn Incorporated, Syosset, N.Y., a corporation of New York Filed July 12, 1965, Ser. No. 471,222 7 Claims. (Cl. 340-459) This invention relates to sheet sensing or detection systems, and more particularly to such a system to be used in inserting machines.

Nowadays large scale mailing is common, as for the mailing of coupons, proxies, advertisements, and other leaflets. The task of selecting, collating and inserting such material in envelopes has been met by the development of so-called inserting machines which have multiple stations, each with an upright magazine in which the coupons or leaflets may be stacked. At each station there is a claw which pulls the lowermost sheet from the magazine, and moves it to a conveyor which receives sheets from all of the magazines and so collates the same.

A problem arises in the event that the claw fails to deliver a sheet from the magazine, and another problem arises when multiple sheets instead of one are removed from the magazine. It has already been proposed to provide sheet detection or sensing means at each station to sound an alarm and/or to stop the machine in the event that no sheet is delivered, or in the event that multiple sheets are delivered at a single station.

The primary object of the present invention is to generally improve such detection systems. More particular objects are to provide a detection system which is simple, inexpensive, dependable in operation, and which uses rollers between which the sheet is moved, thereby avoiding resistance and damage to the sheet. In accordance with a feature and object of the invention a single pair of rollers is used with electrical circuitry for sensing both the absence of a sheet, and the presence of multiple sheets.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the sheet sensor elements, and their relation one to another and to the inserting machine elements, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

FIG. 1 is a fragmentary plan View of an inserting machine to which the invention has been applied;

FIG. 2 is a perspective and largely schematic view, drawn to larger scale, and showing the invention applied to one station of an inserting machine;

FIG. 3 is a vertical section through the machine at one station; and

FIG. 4 is a schematic electrical diagram explanatory of the operation of the detection system.

Referring to the drawing, and more particularly to FIG. 1, the inserting machine comprises a series of stations, often up to six stations, of which four stations are here shown. Each station has a magazine with a stack of the sheets to be inserted, indicated at 12, 14, 16 and 18. The sheets are held in superposed alignment against fixed front walls 20; by upright guide rods. In the present case there are two rods 22 in back of the sheets, and a single rod 24 at each end of the sheet. The location of the rods is adjustable because the sheets may differ considerably in size, although here shown alike.

In front of each magazine there is a claw generally which may be oscillated by a rock shaft 28, and this claw serves to extract the lowermost sheet from the magazine, and to pull it to a conveyor indicated generally at 30. The conveyor moves the sheet, in this case to the left, and by the time a sheet from magazine 12 reaches the left end of the machine, it has had added thereto a sheet from each succeeding magazine, thereby collating the sheets prior to insertion in an envelope. The inserting mechanism per se may be conventional and is not here shown.

Referring now to FIGS. 2 and 3 of the drawing, a stack of sheets is shown at 12, between guide rods 22 and 24 and front plate 20. The claw 26 carried on rock shaft 28 has a fixed jaw 32 and a movable jaw 34. The latter may be opened or closed by means of a rod 36 operated by an arm 38 and a rod 49. The latter is rocked by means not shown. A pull spring 42 serves to normally close the jaws. It will be understood that the jaws are open when they move to the magazine 12, and that they close to grip the lowermost sheet before the claw moves back to a position over the conveyor 30.

The conveyor may be conventional, and as here schematically illustrated, comprises two chains 44 and 46 which are driven by sprockets 48 and 50 carried by a shaft 52. Appropriate studs 54 and 56 are mounted at suitably spaced intervals on the chains 44 and '46, and move through guide slots 58 and 60. There are also stationary side rails 62 and 64, either or both of which may be made adjustable to vary the spacing therebetween. It will be understood that the spacing of the studs and the rotative speed of the shaft 52, are properly related to the speed or repeat cycle rate of the machine to ensure synchronous operation; that is, the chain provides a stud for each extraction of a sheet from the magazine, and by the time the next sheet is extracted and deposited on the conveyor the next stud has come into position to move the same. The complete inserting machine includes driving shafts at least one of which may be considered to he a master or main driving shaft which turns in one to one ratio, that is one rotation for each cycle or sheet extraction of the machine. A crank on that shaft is connected to and rocks the rock shaft 28. All of the magazine stations preferably operate in unison.

To help separate the lowermost sheet for ready seizure by the claw, each station may be provided with a suction pipe; indicated at 68, and may also be provided with a sheet positioning finger 70. This finger has a chisel shaped edge, and is oscillatably carried on a rock shaft 72. It moves into the position shown ahead of the movement of the claw, and so helps hold the lowermost sheet in proper position for seizure by the claw. The finger 70 moves back out of the way as a sheet is being extracted, so that the suction head 68 then may draw the next or then lowermost sheet downward, whereupon the finger 70 again moves into position ahead of the claw.

As so far described, the inserting machine station is conventional. A particular example of such an inserting machine is that known commercially as the Phillipsbu'rg Inserter, made by Bell & Howell Company of Chicago, Illinois.

In accordance with the present invention, a sheet sensing or detection means is added, and this comprises a fixed roller 74 which is located beneath the path of a sheet being extracted by the claw. It further comprises a movable roller 76 carried by a movable carrier 78, which preferably is a lever pivoted on a fixed pivot at 80, and having a generally upwardly extending arm 82. Arm 82 carries and moves an electrical contact 84, preferably with a multiplied motion, that is, the arm 82 of the lever is substantially longer than the arm 78. The contact '84 is a movable contact which cooperates with a stationary contact 86. One contact or the other preferably is adjustable, and in the present case, the movable contact 84 is threade-dly received by arm 82, and its adjustment may be locked by means of a lock nut 88.

The roller 76 is urged into contact with the roller 74, as by means of a pull spring carried on a fixed arm 92. It is convenient to mount roller 74 on insulators, indi- 3 cated at 94, and to mount contact 86 on insulating material, indicated at 96, in which case the lever 78, 82 with the movable roller 76 and the movable contact =84 may be grounded to the machine frame. The system further includes an alarm, in this case a lamp 100-, which directs the attention of the operator to the particular station which is not working properly. The alarm may be audible instead of visible, or both audible and visible. Moreover, means may be provided to automatically stop the machine.

It will be understood from inspection of FIGS. 1 and 2 that the detection rollers are offset somewhat from the claw and therefore do not interfere with movement of the claw between the magazine and the conveyor. The positioning finger 70 also is somewhat offset from the path of movement of the claw, but is offset in opposite direction.

The operation may be described with reference to FIG. 4 of the drawing, which is a schematic electrical diagram. The movable roller '76 and movable contact 84, carried by lever 78, 82, are grounded as shown at 102. The fixed roller 74 and the fixed contact 86 are electrica-lly connected by a conductor 104, and bot-h are connected through conductor 106 to one side of a low voltage source. The inserting machine has a drive shaft or an auxiliary shaft 108 which turns in one to one ratio with the operation of the claw. As a part of the present system such a shaft 108 is provided with a cam 110 operating a suitable timing switch 112, which is connected in series with the low voltage source. The cam is so oriented that the switch 112 is closed in synchronism with the sheet movement through the rollers, and the said switch is open when there is no sheet supposed to be moving between the rollers.

The switch 114 is a manually operated witch to make the circuit inoperative when the machine is not in use. The low voltage source is connected to the coil 116 of a relay, the circuit being completed at the ground 118. When the relay is energized its movable contacts 120 and 122 are pulled from upper position to lower position. These contacts are connected to a power supply source, and in upper position they operate the driving motor 126 of the inserting machine. When moved to lower position, the motor 126 is stopped, and the power supply source is connected to the alarm 100.

It will be seen that if the claw fails to pull a sheet from the magazine when the timing switch 122 is closed, the contact of movable roller '76 against fixed roller 74 completes the relay circuit and so energizes the alarm and stops the machine. The contact 84 is adjusted to just close when two sheets are moved between the rollers. The contacts remain open when there is only one sheet between the rollers, as there should be. Thus, if the claw pulls multiple sheets from the magazine, the movable roller 76 is moved away from the fixed roller 74 far enough to close the contacts 84, 86, thereby energizing the relay, which in turn works the alarm and stops the machine.

It will be understood that in practice the circuitry is slightly more complex in several respects. One is that with multiple stations there may be a single timing switch 112, but there are multiple relays and alarms, one for each station, so that the attention of the operator will be directed not only to the machine in general, but also to the particular station causing trouble. In such case operation of any relay should stop the motor, even though the other relays have not been operated. The connection to the motor may be to a master relay, and thence to a motor starter circuit, instead of the simple direct connection to the motor suggested in FIG. 4.

In practice the relay has a holding contact, indicated at 128, and so connected as to keep the relay energized once it has been operated. The alarm then remains on and the driving motor remains stopped, regardless of the position of the cam 110.

The low voltage circuit avoids possible injury to the operators of the inserting machine.

It is believed that the construction and operation of my improved sheet sensing or detection system, and its relation to a typical inserting machine, as well as the advantages of the same, will be apparent from the foregoing detailed description. The system is simple, inexpensive, dependable, and uses rollers which do not impede the travel of the sheet nor damage it. A single pair of rollers serves for nosheet detection and for multiple-sheet detection.

It will be apparent that while I have shown and described my invention in a preferred for-m, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. A no-sheet and multiple-sheet detector comprising a voltage source, a fixed metal roller mounted in the path of a sheet, a movable metal roller carried on a pivoted lever, means urging the movable roller into contact with the fixed roller, 21 contact carried and moved by the pivoted lever, a fixed contact engaged by said movable contact when said movable roller is moved away from the fixed roller by multiple sheets passing therebetween, said fixed roller being electrically connected to said fixed contact and both to said voltage source, the movable roller and movable contact both being electrically connected to the other side of the voltage source, and an alarm responsive to contact either of said rollers, or of said contacts.

2. A no-sheet and multiple-sheet detector for use at a sheet moving station having a driving shaft, said detector comprising a voltage source, a fixed metal. roller mounted in the path of a sheet, a movable roller carried by a movable carricr, means urging the movable roller into contact with the fixed roller, a cam operated switch in series with said source and so driven by said shaft that the switch is closed in synchronism with the sheet movement through the roller, a movable contact carried by the movable carrier, a fixed contact engaged by said movable contact when said movable roller is moved away from the fixed roller by multiple sheets passing therebetween, said fixed roller being electrically connected to said fixed contact and both to said voltage source, the movable roller and movable contact both being electrically connected to the other side of the voltage source, and an alarm for said station responsive to contact either of said rollers or of said contacts simultaneously with closing of said cam operated switch.

3. A no-sheet and multiple-sheet detector for use at a sheet moving station having a driving shaft, said detector comprising a low voltage source, a relay energized therefrom, a cam operated switch in series with said source and so driven by said shaft that the switch is closed in synchronism with the sheet movement, a fixed roller insulatedly mounted in the path of a sheet, a movable roller carried on a pivoted lever, resilient means urging the movable roller into contact with the fixed roller, an adjustable contact carried and moved by the pivoted lever with multiplied motion, an insulatedly mounted fixed contact engaged by said adjustable contact when said movable roller is moved away from the fixed roller by multiple sheets, said insulated fixed roller being electrically con nected to said insulated fixed contact and both to said low voltage source, the movable roller and movable contact both being electrically connected to the other side of the low voltage source to complete the relay circuit, a higher voltage source, an alarm for said station, and relay contacts responsive to energization of the relay from the low voltage source for connecting the higher voltage source to the alarm and so arranged as also to stop the operation of the station.

4. A no-sheet and multiple-sheet detector for use at a magazine station of an inserting machine having a claw movable toward and away from the magazine to pull a sheet from the magazine to a collating conveyor, said detector comprising a voltage source, a cam operated switch in series with said source and so driven by a shaft of the inserting machine that the switch is closed in synchronism with the sheet pulling operation of the claw, a fixed roller mounted in the path of a sheet moving from the magazine to the conveyor, a movable roller carried by a movable carrier, means urging the movable roller into contact with the fixed roller, an adjustable contact carried by the movable carrier, 21 fixed contact engaged by said adjustable contact when said movable roller is moved away from the fixed roller by multiple sheets, said fixed roller being electrically connected to said fixed contact and both to said voltage source, the movable roller and movable contact both being electrically connected to the other side of the voltage source, and an alarm for said station responsive to contact of said rollers or of said contacts.

5. A no-sheet and multiple-sheet detector for use at a magazine station of an inserting machine having a claw movable toward and away from the magazine to pull the bottom sheet from the magazine to a collating conveyor, said detector comprising a low voltage source, a relay energized therefrom, a cam operated switch in series with said source and so driven by a shaft of the inserting machine that the switch is closed in synchronism with the sheet pulling operation of the claw, a fixed roller insulatedly mounted in the path of a sheet moving from the magazine to the conveyor, a movable roller carried on a pivoted lever, resilient means urging the movable roller into contact with the fixed roller, an adjustable contact carried and moved by the pivoted lever with multiplied motion, an insulatedly mounted fixed contact engaged by said adjustable contact when said movable roller is moved away from the fixed roller by multiple sheets, said insulated fixed roller being electrically connected to said insulated fixed contact and both to said low voltage source, the movable roller and movable contact both being electrically connected to the other side of the low voltage source to complete the relay circuit, a higher voltage source, an alarm for said station, and relay contacts responsive to energization of the relay from the low voltage source for connecting the higher voltage source to the alarm and so arranged as also to stop the operation of the inserting machine.

6. A no-sheet and multiple-sheet detector for use at a magazine station of an inserting machine having a drive shaft and having means movable toward and away from the magazine to pull a sheet from the magazine to a collating conveyor, said detector comprising a voltage source, a fixed metal roller mounted in the path of a sheet moving from the magazine to the conveyor, a movable metal roller carried by a movable carrier, means urging the movable roller into contact with the fixed roller, 21 contact carried by the movable carrier, a fixed contact engaged by said movable contact when said movable roller is moved away from the fixed roller by multiple sheets passing therebetween, a cam operated switch in series with said source and so driven in synchronism with said drive shaft of the inserting machine that the switch is closed in synchronism with the passage of a sheet through the rollers, said fixed roller being electrically connected to said fixed contact and both to said voltage source, the movable roller and movable contact both being electrically connected to the other side of the voltage source, and an alarm for said station responsive to contact either of said rollers or of said contacts while the cam operated switch is closed.

7. A no-sheet and multiple-sheet detector comprising a voltage source, a fixed metal feeler mounted in the path of a sheet, a movable metal feeler, means urging the movable feeler into contact with the fixed feeler, an electrical contact carried and moved by the movable feeler, a fixed contact engaged by said movable contact when said movable feeler is moved away from the fixed feeler by multiple sheets passing therebetween, said fixed feeler being electrically connected to said fixed contact and both to said voltage source, the movable feeler and movable contact both being electrically connected to the other side of the voltage source, and an alarm responsive to contact either of said feelers, or of said contacts.

References Cited UNITED STATES PATENTS 869,324 10/1907 Obert 340-259 X 2,257,465 9/1941 Higginbottom 271-57 X 2,515,787 7/1950 Moe 340-265 X 3,073,592 1/1963 Golding 340-259 X 3,155,244 11/1964 Rogers et al 271-57 X 3,174,005 3/1965 Moneypenny ZOO-61.13 3,176,981 4/1965 Vandeman 271-57 3,182,147 5/1965 Larson 340-259 X 3,194,554 7/1965 Hilpman et al 271-57 3,287,015 11/1966 Preuss et a1. 271-57 OTHER REFERENCES IBM Technical Disclosure Bulletin, vol. 7, No. 8, January 1965.

JOHN W. CALDWELL, Primary Examiner. D. L. TRAFTON, Assistant Examiner. 

1. A NO-SHEET AND MULTIPLE-SHEET DETECTOR COMPRISING A VOLTAGE SOURCE, A FIXED METAL ROLLER MOUNTED IN THE PATH OF A SHEET, A MOVABLE METAL ROLLER CARRIED ON A PIVOTED LEVER, MEANS URGNG THE MOVABLE ROLLER INTO CONTACT WITH THE FIXED ROLLER, A CONTACT CARRIED AND MOVED BY THE PIVOTED LEVER, A FIXED CONTACT ENGAGED BY SAID MOVABLE CONTACT WHEN SAID MOVABLE ROLLER IS MOVED AWAY FROM THE FIXED ROLLER BY MULTIPLE SHEETS PASSING THEREBETWEEN, SAID FIXED ROLLER BEING ELECTRICALLY CONNECTED TO SAID FIXED CONTACT AND BOTH TO SAID VOLTAGE SOURCE, THE MOVABLE ROLLER 